All entries for Thursday 24 November 2011
November 24, 2011
Over recent years, the Three Gorges Dam in China has warranted much debate about its effects. Three Gorges Dam is a hydroelectric dam located along the Yangtze River by the town of Sandouping. It is a monstrous project, and the dam itself has taken countless years of planning and construction, at a construction cost of 180 yuan. Many have seen it as a great historic engineering, social and economic success, but what about environmentally?...
Initially, there was an aim to limit greenhouse gases, and I think that that task has been met so far. But there's a much higher risk of landslides, and some 1.3 million people have been displaced.
In terms of generating power, it is a very well-executed project. It is the world's largest capacity hydroelectric power station with a total capacity of 20,300 MW. Eventually, it is believed that when it reaches it's full capacity, it will have a capacity of 22,500 MW. That's substantial enough for every person in the UK and Australia to watch their own large plasma TV at the same time!
There will be 32 generators in all, 30 of which will be main, and there will be 700 MV worth of capacity in each one.
Three Gorges Dam has reduced a lot of emissions. 31 million tonnes of coal consumption is reduced on an annual basis. Subsequently, this prevents 100 million tonnes worth of greenhouse gas emmissions from polluting the environment, as well as millions of tonnes of dust, one million tonnes of sulfur dioxide, 370,000 tonnes of nitric acid, 10,000 tonnes of carbon monoxide, and a significant amount of mercury.
During the years between 2003 to 2007, power production equalled that of 84 million tonnes of standard coal, reducing carbon dioxide by 190 million tonnes, sulfur dioxide by 2.29 million tonnes and nitrogen oxides by 980,000 tonnes.
Yangtze's barge capacity sixfold has been increased by the dam. This has led to the reducing of carbon dioxide emmissions by 630,000 tonnes.
But with the good comes the negatives. Sedimentation projections are not agreed upon, and the dam also sits on a seismic fault. 80% of the area's land is experiencing erosion right now. From this, 40 million tonnes of sediment is deposited into the Yangtze River annually. However, the flow is slower above the dam, and a lot of the sediment is to settle there, rather than flowing downstream.
Downstream riverbanks are predicted to become more vulnerable to flooding. And the dam's upstream face could be breached, from the weight of the reservoir water and earthquake-induced peak ground acceleration. Landslides have occured from erosion in the reservoir.
So overall, in my opinion, the Three Gorges Dam project has a good impact on the environment, most notably due to the huge amount of carbon emmissions that have and will continue to be reduced. Although I haven't discussed about it, China has also reaped the benefits of the dam economically. There will always be risks for the dam, rather inevitably. But for the foreseeable and more distant future, the Three Gorges Dam, I think, will carry on producing the goods. What do you think about it's effect on the environment?
Quite a long time ago, i compiled a project on Jatropha carcus, a plant from the family Euphorbiaceae. The name is derived from the Greekwords ἰατρός (iatros), meaning "physician," it was mainly used in the past as medicine until its other beneficial uses came to surface (production of biofuel).
It then became one of the best candidates for future biodiesel production. the biodiesel is extracted from bio-oil which is made up of many compounds. these all separated through a process known as transesterification. all of these used in different industries.
to augment to this fascinating phenomenon, the diesel obtained from the plant is said to burn with a clean flame, therefore green house effect reduced.
taking into consideration the effect that the recession has had there, is a need to find other economical ways in extraction of fuel. This amongst others is quite easy and cheap to run, but we all no that everythin has its bad sides and jatropha carcus is no exception. weighing the merits and demerits what do you think is best?